/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.concurrent;

import org.apache.flink.util.Preconditions;

import java.time.Duration;

/**
 * An implementation of {@link RetryStrategy} that retries at a fixed delay.
 */
public class FixedRetryStrategy implements RetryStrategy {
	private final int remainingRetries;
	private final Duration retryDelay;

	/**
	 * @param remainingRetries number of times to retry
	 * @param retryDelay delay between retries
	 */
	public FixedRetryStrategy(int remainingRetries, Duration retryDelay) {
		Preconditions.checkArgument(remainingRetries >= 0, "The number of retries must be greater or equal to 0.");
		this.remainingRetries = remainingRetries;
		Preconditions.checkArgument(retryDelay.toMillis() >= 0, "The retryDelay must be positive");
		this.retryDelay = retryDelay;
	}

	@Override
	public int getNumRemainingRetries() {
		return remainingRetries;
	}

	@Override
	public Duration getRetryDelay() {
		return retryDelay;
	}

	@Override
	public RetryStrategy getNextRetryStrategy() {
		int nextRemainingRetries = remainingRetries - 1;
		Preconditions.checkState(nextRemainingRetries >= 0, "The number of remaining retries must not be negative");
		return new FixedRetryStrategy(nextRemainingRetries, retryDelay);
	}
}
